ios - UIDocumentPickerViewController 只显示最近标签

Question

我一直在尝试UIDocumentPickerViewController在 SwiftUI 中实现 a ，但运气不佳。当我在工作表中显示视图时，即使模拟器中有文件，也只有一个空白的“最近”选项卡（如下所示）。如何从 iCould drive 或“在我的 iPhone 上”选择？

文件选择器.swift

struct FilePicker: UIViewControllerRepresentable {
    class Coordinator: NSObject, UIDocumentPickerDelegate, UINavigationControllerDelegate {
        
        var parent: FilePicker
        
        init (_ parent: FilePicker) {
            self.parent = parent
        }
        
        public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
            print("chosen")
            guard let documentURL = urls.first else {
                return
            }
            
            if let data = try? Data(contentsOf: documentURL) {
                parent.image = UIImage(data: data)
                parent.presentaionMode.wrappedValue.dismiss()
            }
            else {
                return
            }
        }
        
        func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
            print("cancelled")
        }
    }
    
    @Binding var image: UIImage?
    @Environment(\.presentationMode) var presentaionMode
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    func makeUIViewController(context: UIViewControllerRepresentableContext<FilePicker>) -> UIDocumentPickerViewController {
        let pickerViewController = UIDocumentPickerViewController(forOpeningContentTypes: [.image, .jpeg, .png, .pdf], asCopy: true)
        return pickerViewController
    }
    
    func updateUIViewController(_ uiViewController: UIDocumentPickerViewController, context: UIViewControllerRepresentableContext<FilePicker>) {
    }
}

内容视图.swift

struct ContentView: View {
    @State var image: Image?
    @State var activeSheet: ActiveSheet?
    @State private var inputImage: UIImage?
    
    var body: some View {

            ZStack{
                 //Stuff in here
            }
            .sheet(item: $activeSheet, onDismiss: loadImage) { item in
                switch item {
                
                case .photo:
                    PhotoPicker(image: $inputImage)
                case .file:
                    FilePicker(image: $inputImage)
                case .demo:
                    DemoPicker(image: $inputImage)
                }
            }
        }
    }
    
    func loadImage() {
        guard let inputImage = inputImage else {
            print("failed input image")
            return
        }
        image = Image(uiImage: inputImage)
        showMenu = false
    }
}

enum ActiveSheet: Identifiable {
    case photo, file, demo
    
    var id: Int {
        hashValue
    }
}